J.,
This sounds like the same problem my brother had with his very intelligent son Zachary at a similar age. They live in Texas. I remember the REAL issue being safety. What if the whole cabinet fell on top of the monkey boy while he chimbed?? My brother did a lot of securing furniture to the studs in the walls, knowing no matter how much you have your eye on the child, there will still be times the monkey gets past you. Or the TV crash down on his sweet, too smart of a brain. The concerns and the aggrivations I can see you must be going through. I know my brother ever put gates that couldn't be opened by the child....I don't mean one gate...but a gate on a lower part, then one ABOVE that one....lol...Or here's an idea....for your room....hang some bells that will make noise when he attempts going into that room....Or another idea...I was at CVS, in the isle with car stuff, telephone wiring and "as seen on TV" stuff...and I saw a gadget that goes on the door handle, when it it messed with ever so slightly (handle turned the tiniest bit), an alarm goes off. Maybe you can talk with him about all the extra stuff you are going to have to do to ensure his safety and your sanity...and the money spent does NOT make you happy either...but that you will do whatever you have to to keep him out of your things and into his own. When these alarms go off, and you bust him in the act...instead of askingyou, tehn he will have a mandatory time out or something that might be his favorite taken away for awhile. Follow through. Obvioulsy spankings do not work. Follow Super Nanny's ideas. Look her up or watch an episode. She is very GOOD!! Tell him you will lower things that he has proven he can be trusted with....example...DVD and VHS tapes...after a lesson if needed. Books that he is good with, crafts, as long as keep the art on the paper provided, and not an "artist' on the walls." Buy a lock door (with a couple of keys) for a room or two (you can even get them to be the same key...codes are on the back to get them to match- I bought several at Lowes for about 8-10 dollars a piece, and that is where his fishes food will go, change -money- will go (My ex is a ped GI surgeon, and he says that the surgery that he preforms the most is a child swallowing a penny. It blocks important passagways and HAS to be removed, the darn PENNY!)....all things that he has abused and things you tell him why they are bad for him to handle.
He will continue to be a monkey, but with locks, furniture safety equiptment, alarms on a door (about 20 bucks) or even a bundle of bells hanging on a backside of a door- up high, will at least give you a heads up before you find him hanging from a chandelier!! While he is in this stage, get him into a class where they allow them to rock climb. There are so many places that have it available here in Indy, maybe, if y ou are far, you can look it up. It is very secure and guided climbing of a rock wall. It may fill the desire for him...tell him to keep the monkey at his rock ckimbing class, and your baby boy can be at home with you. And that you will be most happy to retreive what is high...while you are around....if it is high...that there is probably a reason for that!! lol...
One more thing....after a year or 2...It will pass!! Spiderman will get deep into another frightening and impossible stage that keeps you YOUNG!!
Good luck and God Bless!!